Switch



May 2, 1933. A. ALSAKER 1,906,505

SWITCH Filed April 2.9, 1929 2 Sheets-Sheet 1 May Z, 1933.

A. ALSAKER SWITCH 2 Sheets-Sheet 2 Filed April 29, l1929 l-VI PatentedMay `2, 19.33y

UNITE-D vsTA-.'rfas PATENT OFFICEl A ALFRED ALsAxER, OFoIIICAGOi,"ILLINOIs, AssIGNoR fro rrIIE DELTAs'rAR ELECTRIC. COMPANY, orCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS f SWITCH Application LledrApril 29;

This application ay continuation part of my copending application"Serial No. 237,678, tiled December 5',f1927,"andlthis invention relatesto electric switches, more particularly to the` outdoor gang yoperatedtype such` as arecommonly employedforv power disconnect purposes.V Whilethe invention is particularl applicable to this service, it is notintended to limit itto that use. v l

VSwitches of the present type areinfre-` quentlyoperated and afterremaining closed for long periods yof time during which they aresubjectedto ally :sorts of weather ,lconditions, there is a tendency forthe` switch Vcontacts to stick together. Ice or sleet' may form on thecontacts-if thecontacts'areeX-r, posed, thus rendering opening `of vtheswitch rather difficult. `Unless special means is employed for.Yseparating the contacts,`the

insulator stacksl supportingthe contacts may be subjected Vtoexcessively `high mechanical stresses. It is a particularobj'ect ofthepresenty invention toY provide .a simple switch mechanism vwherein thepreliminary ice breaking movementof the switchicon-k tacts is obtainedwithout inducing excessive mechanical stresses inthe insulators. y.

The present form of switch com rises two. su )porting insulators upononeo `which a re atively long switch blade is Inountedrand upon theotherof which, al relativelyr short switch contact is mounted.. 4Bothinsulators are rotatable and are mechanically in-` terconnected so thatrotation of oneof the insulators produces ,rotation of the other. Theblade engages the contact ywith a wiping movement thus forming a cleancontacting surface between the blade. andits contact. Upon opening theswitch `the blade and contact separate with a shearingmotion, andbecause of the relativelyl longlength of the blade and therelativelyshort,turning radius of the rotatable contact member, a greatshearing force is 'generated which is suflicient to break the bindbetween the blade and the contact member whether this binding is causedby corrosion, orv byice or sleet. This great shearing force, is, ofcourse, due to the fact that theblade and the contact 1929. sejriaiN0.f35s,s93.

likewise whenthe switch is closed thesleet shield minimizes or preventsthe formation.

of ice ybetween the switch blade and the contact. e

The sleet shield is, in the present embodiment of the invention, in theform of a plate overhanging theswitch contact and secured thereto. Bythis arrangement the inertia of the moving mass is'considerablyreduced.)

e The attainment ofv the above and further objects `ofthe inventionwilllbe apparent from' the following specification taken in conjunctionwith the accompanying draw`r ings forming a part thereof.

In the drawings: 1

Fig. 1 is a side elevational view of the switch ,forming thepresentinvention;

Fig. 2isa bottom vplan view of the switch operating mechanism; l y Y l fFig. 3 isoan enlarged view showing the switch contact'and manner ofsecuring it to insulators; e y

Fig`.4 is abottom plan view of Figp3;

v Fig; 5l `isa fragmentary section taken along the line 5f5 of Fig. 3.

The switch shown in Fig. 1 is of the under'slung type and comprises two'insulator stacks, 1 and 2, support from a base 3 which may be in theform of a channel as is the usual' construction. The insulator stacks I2 are connected to the Vchannel base 3 through rotarybearings It and 5which are interposed betweenthe channel 3 and the insulator caps -6 and7.5; Y e

V The rotary-'bearings may befof the type disclosed'in my copendingapplication, Serial No.y 137,926 filedy September 27, 1926. Theinsulator stackA 1 is fitted at `its lower end ywith an adapterl()suitably vsecured to the insulator pin 11 rby means of bolts, 12. A`contact 13 inthevform ofa substantially flat rectangular plate is boltedto the adapter 10 byv means offour 'bolts indicated at 14.

nno

The bolts 14 also serve to secure a T shape reenforcing member 15 to theblade 13. A bearing stud 18 having two forks at 19 is secured to thereenforcement member 15 by bolts 20 and acts as a bearing member for alug support 22 having a projecting lug 23 to which a lead in line forthe switch may be attached. The lug support Iis held in the bearing studand is tree to rotate with respect to the lug support. As a result ofthis arrangement the lug support 22 is held stationary by the line thatis connected to the arm 23 while the bearing stud rotates with theinsulator stack 1. "A flexible conductor in the form of ,a copperbraided wire 24 connects lthe lugV support 22 withr the contact 13 sothat all of the current flowing through this switch is carried by theconductor 24 and does not have to pass through s the bearing member.

A bracket 28 is bolted to the contact 13 by means ottwo bolts 29 andsupports a sleet shield 30 which is riveted or otherwise suitablysecured to the bracket. The sleet shield 30 overlies the end of thecontact 13 that is engaged by the switch bladein a manner `to bel vmorefully set forth presently and prevents the accumulation of ice or sleetupon the contact. j

A switch blade is secured to the bottom of the Iinsulator stack 2 insubstantially the same manner as is the contact`13, an adapter 36similar to they adapter 10 being j interposed between the switch `blade35 and the insulator pin 11. The blade 35has a T shaped reenforcingmember 38 secured to the bottomV thereof and this reenforcing memberserves as a support for a bearing stud 40 of a. construction identicalwith the construction of the bearing stud 19. The bearing stud 40supports the lug support 41 identical tothe lug support 22 upon theinsulator 1. A flexible braided copper con- '1 ductor 42 connects thelug support with the switch blade 35. A pair'of contact jaws45 aremounted upon springs 46 at the end'of the switch blade 35, said contactjaws being adapted to receive the contact 13 between them.

An operating lever 5() is adapted to ro-A tate the ,insulator stack 1,said lever being secured to the bearing member 4 as shown in my abovereferred ,tofapplication The l rotary motion of the insulatorstack 1 isthe switch to open due to the force between the contact 13 and theswitch blade 35 by reason of current flowing through the' switch.

To open the switch the operating lever 50 is rotated in a counterclockwise direction as seen in Fig. 2, thereby rotating the switch bladein a clockwise direction as seen in Fig. 2. It is to be noted that atthe commencement of the switch opening movement the switch contact 13has a greater angular velocit than the switch blade 35. Due to the togge action of the members shown a relatively great force may be exerted tobreak the switch blade 35 from the contact 13 through any ice orcorrosion that may have formed. When the switch is closed the reverseoperation occurs and the contact 13 is moved between the contact jaws onthe switch blade 35 with a shearing action. This shearing action tendsto clean the switch contacts as the switch is closed thereby maintaininggood electrical contacts. It is to be noted that the edge of the switchcontact 13 is beveled and that the contact jaws 45 flare outwardly. Thisfacilitates the movement of the contact between the' jawsin that itserves as a guide for guiding the contacts into the jaws during theswitch closing movement.

' There Ais a distinct advantage in arranging the "levers 51 and 52 sothat they 'are in substantial Valignment when theA switch is closed andin providingan operating connection such as the lever for rotating theinsulator. stack 1, and from this stack transmittingl the motion to thestack 2. In switches of this kind the operating lever is generallyturned by means of a series of links which extend for an appreciabledistance from the switch. The motion is transmitted through these linksto the lever 50. Assume that the switch as initially installed isadjusted so that when the operating handle or the like at the end of theactuating link work is actuated to its extreme position the motion istransmitted to the crank 50 to rotate the insulator stacks 1 and 2 intothe closed position as shown in the drawings; After a period of time itmay happen that a certain-amount of free play is developed ice meansthat under such condition when the switch is actuated to its closedposition. the contact 13 that is mounted upon the insulator stack 1 willbe five degrees out of its true closed position. The same applies to thecrank 51 that transmits the motion through the lever 52 to the insulatorstack 27 and, when the operating mechanism has been moved to its fullclosed position the lever 51 will be approximately live degrees out ofthe position shown in Figure 2 in the example assumed. Under thoseconditions and 45 will vtherefore;engagey oneanotljler.y

with' theresult that the circuit throughy the switchis closed. n the'other hand, as-

sume thatlthe driving lconnection 'of the lever were made to theinsulator 2 instead of to the insulator 41.A f Under such condition ifthe same amount of free playshould'develop' in the link work thattransmitsmotion tothe lever thenthe switch bladewould reach'its closedposition' which would'be ve degrees out of its true position. Due tothegreat length of the switch blade such ay Treat difference yin the,angular position `o? the switch blade mayy cause it to fall short ofengaging the switch contact 13. The same result does not follow from ashort angu lar displacement of the contact 13 due to the fact that thiscontact is vor' a much smaller length.

There is an additional advantage in locating the lever- 50 so that lthe'motion is irst transmitted to the contact supporting insulator and fromit to the blade support ing insulator, This is due to the followingcondition: l Y,

Suppose that the switch has remained closed for a long period of timeandthe cony tacts have become corroded together, rendering the openingoperation difficult. A certain amount of freeveplay or looseness isinherently present in the connection between the insulators and upon theapplication'of a turning forceV to the crank 50 to open the switch theforce is transmitted to the contact 13 which commences to turn to breakthe bind between it and the contactl 55. This turning commences veryslightly in advance of the rotation of the switch bladev due to theinherent presence ofeven trifling amounts of free play. Thus the forcevwhich tends to free the contacts from one another is transmitted at arelatively short radius whereby the stresses induced in theinsulators issmall. Now, by reason of theffact that the crank 51 and the connectingrod 52 are Vin substantial alignment when the switch is closed asmall-angular movement of the insulator 1 toward the open positionproduces substantially no movement of the `-insulator 2, hence all ofthe el'ort necessary to break the bind between the Contact plate 13 andthe contact 35 may be transmitted through the insulator 1 at therelatively `short radius rather than through the insulator 2 and therelatively long blade. This would notbe true if the crankf 51 and theconnecting rod 52 were not substantially in alignment when the switch isclosed, evenif the actuating force were applied to the crank 50connected tothe insulator 1' as, shown. Onthe vother hand if thevoperating lever 50 wereE 'directly connected-*to the insulator' 2 andyfrom this insulator the connection: ex'V tended to the insulatorv 1then theinitial turning movement would necessarily have lto Abetransmitted to the blade 3'51and,"sinc'e this blade' is relativelylong,'there would be appreciable stresses induced in'theinsulator werein alignment when the switch is'closed.-

-` In compliance 4with. the vrequirements of the'patenty statutes Ilhave herein shown and described a preferred embodiment of my in'-vention. It is however, to be understood that the'invention isnotlimited to the precise construction shown, the Vsaine being' Vmerelyillustrative.

W hat I considerrnew and desire to secure by Letters Patent is alfAn'electric switch comprising a relatively short contact and arelatively Ylong switch blade both movable into and outffofengagementjwith one another, separate rotatable insulators for the`blade and the con-` tact, `means for rotating Y the contactv actuainginsulator to rotate the contact, 'and means comprising a .crankmechanism between the insulators yfor transmitting mo; tion to the bladeactuating insulator, said crank mechanism being approximatelyA atits'dead center position wheny the switch is closed.il 2. Anf' electricswitch including a pair of spaced. rotatable insulators, a relativelyshort contactrrotated by one 'of the insula-y tors, a relatively-longVswitch blade rotated by therotherinsulator, said blade and con-ktact-being rotatedby` their respective insu-4 lators int'oand out ofengagementwith one another, means for rotating the contact acI` tuatinginsulator, and means including a crank for rotating the blade actuatinginsulator, said crank being 'approximately `at its when the switch isVdead center position ClOSed; l. v 3'.' An electric switch including apair of spaced rotatable insulators, a relatively short contact-rotatedby one of the insulators, a `relatively'longswitch blade rotated by theother insulator, said blade and contact being rotated by their'respective' insulators intol 4."An electric switch including arelatively short contact andV a'relatively long switch blade bothmovableinto and out of engagement ywith lonev another, and means for Aimpartingak relatively great initial angular motion to the contact' and anegligible an-V fik its"- gular motion to the 'bladel `to initial-lybreak the bind between ythe blade and the contact.

5. An electric switch including apair of rotatable v insulators,cooperating contact making members actuated by the insulators, means forlrotating one ot the insulators, and means including a crank. connectinthe two insulators for transmitting motion rom said one insulator to theother insulator,said crank being approximately at its-deadcenterpositionwhen the switch is closed. i

6. The method of separating a. switch blade from its contactwhichcomprises, first retaining the bladey substantially stationary andturning the contact about a short radius to break the bind betweenA thecontact and the blade,` and then actuating the blade away romthecontactto its "full open posi-V tion. i

7. A, switch comprising a` rotatably mounted switch blade, a. rotatablelcontact adapted to be engaged thereby, and means for forcing -thecontact intoand out of engagement with said blade, said means vincludingmeansv for simultaneously imparting a relatively great motion to theportion of the contact that engages the bladey and a negligible motionto the contacting portion of the blade upon the initial switch openingmovement. C, j l; i

8. A switch including amovable switch blade, a contact at the endthereof, a second contact adapted to be engaged :by the first contactand forced into rm engagement therewith, means for actuating-,the secondcontact to loosen the engagement between the two while the switch bladeis maintainedsubstantially stationary, and means for thereafter swingingsaid switch blade away from said second contact.V Y

v 9. An electric switch including ,a pair of crank arms, a connecting.rod connecting `the two, one of the cranks constituting the drivingkcrank and the otherl constituting the driven crank, said driving crankhaving a normal switch open positionjand a normal switch closedposition, said drivingccrank and connecting rod beingv in substantiallytheir dead center position when `the driving crank is in its normalswitch closed position, insulators connected to and actuated with therespectivercrank arms, and cooperating contact making members actuatedby the respective insulators into and out of engagement with oneanother. .i

10. An electric switch including `a pair of crank arms, a connectingrodconnecting .the two, one of the cranks constituting the o driving crankand the other constituting the drivenV crank, said driving crank havinga normal switchopen position and a normal switch closedposition,v saiddriving crank and connecting rod being in substantially their deadcenter position whenthe driving crank is in its normal switch closedposi# tion, insulators connected tor and movablewith said crank arms, arelatively short contact mounted on the insulator connected with the`driving crank arm, and a cooperating relatively long switch bladeactuated by the vother insulator, l 11. switch `ofthe type wherein arelatively short contact is engaged by a`relatively'longvblade and theswitch is opened by rotating the contact about a comparatively shortradius and the blade about a comparatively long radius, characterized bythe; fact that the linear velocity of the end of contact is maintainedappreciably above the linear velocity of the contacting end ofthebladeduring the initial switch opening operation., o i

In witnessfwhereof, `I hereunto subscribe my namethis 23rd day ofApril1929.

A o ALFRED ALSAKER.`

